Sometimes words aren't needed.
Remus traipsed back from the hospital wing.
Sirius buys a TV and they watch a film.
Sirius wakes from a nightmare.
Remus has noticed Sirius touching him more than usual and confronts him.
What was running through Sirius' mind during the confrontation at the end of Harry's third year? Sirius POV. Very short. No pairings.